ABSTRACT
Isolated low high-density lipoprotein cholesterol (HDLc) is a well-known risk factor for cardiovascular disease and is associated with arterial endothelium dysfunction. Several studies have shown that cholesterol lowering in patients with hypercholesterolemia improves endothelial function, but the effect of treating low HDLc levels remains unknown. We studied the effect of increasing HDLc on endothelial function in patients with coronary artery disease (CAD) and isolated low HDLc (HDLc) <0.91 mM, low-density lipoprotein cholesterol (LDLc) <4.1 mM, and triglycerides <2.8 mM. Flow-mediated endothelium-dependent dilatation (FMD) in response to reactive hyperemia was measured by brachial ultrasound, before and after bezafibrate treatment (400 mg daily for 6 months) in 16 patients with CAD and impaired FMD (<10%). After bezafibrate therapy, HDLc increased from 0.79-1.0 mM (p = 0.0008) at the expense of both HDL2 and HDL3 subfractions, apolipoprotein A-I increased from 1.04-1.19 g/l (p = 0.0012), and fibrinogen decreased from 4.45-3.39 g/l (p = 0.0007). The impaired FMD increased after bezafibrate treatment from a median of 2.5-12.3% (p = 0.0004). Endothelial function was normalized in eight patients (50%), improved in four (25%), and did not change in four (25%). These observations indicate that in patients with isolated low HDLc and CAD, bezafibrate treatment improves endothelial function of brachial arteries, increases HDLc and apolipoprotein A-I, and lowers fibrinogen concentrations.
Subject(s)
Bezafibrate/therapeutic use , Coronary Artery Disease/physiopathology , Endothelium, Vascular/physiopathology , Hypolipidemic Agents/therapeutic use , Tangier Disease/physiopathology , Aged , Bezafibrate/pharmacology , Brachial Artery/drug effects , Coronary Artery Disease/drug therapy , Endothelium, Vascular/drug effects , Humans , Hypolipidemic Agents/pharmacology , Male , Middle Aged , Statistics, Nonparametric , Tangier Disease/drug therapy , Vasodilation/drug effectsABSTRACT
BACKGROUND: The aim of this study was to analyze the percentage of individuals with hypoalphalipoproteinemia and isolated hypertriglyceridemia which would not be detected if only total cholesterol were included in the initial detection of dyslipemia. METHODS: Five hundred forty-one individuals participating in a study concerning factors of cardiovascular risk were included in the present study which consisted in a survey on risk factors and a medical examination. The population studied was divided according to the concentration of total cholesterol (TC) in desirable concentrations (5.2 mmol/l), intermediate (5.2-6.2 mmol/l) and elevated (6.2 mmol/l). The concentrations of cholesterol bound to high density lipoproteins (cHDL) less than 0.9 mmol/l and of triglycerides (TG) greater than 2.3 mmol/l were considered as high risk. RESULTS: Hypoalphalipoproteinemia would not be detected in 2.9% of the population studied (IC 95%: 1.5%-4.3%) and isolated triglyceridemia in 2.4% (IC 95%: 1.1%-3.7%) if the cHDL and the TG were only determined in the individuals who had high or elevated CT concentrations and two or more cardiovascular risk factors. CONCLUSIONS: These data support the efficacy of CT as the only test for initial detection of dyslipemia and question the convenience of initial quantification of cHDL and triglycerides in all cases as some authors request.
